Evaluation of Near Subsurface 2D Vs Distribution Map using SPT-Uphole Tomography Method

SPT-업홀 토모그래피 기법을 이용한 지반의 2차원 전단파 속도 분포의 도출

  • 방은석 (한국과학기술원 건설 및 환경공학과) ;
  • 김종태 (한국과학기술원 건설 및 환경공학과) ;
  • 김동수 (한국과학기술원 건설 및 환경공학과)
  • Received : 2005.11.17
  • Accepted : 2006.03.24
  • Published : 2006.05.31

Abstract

SPT-Uphole tomography method was introduced for the evaluation of near subsurface shear wave velocity (Vs) distribution map. In SPT-Uphole method, SPT (Standard Penetration Test) which is common in geotechnical site investigation was used as a source and several surface geophones in line were used as receivers. Vs distribution map which is the triangular shape around the boring point can be developed by tomography inversion. To obtain the exact travel time information of shear wave component, a procedure using the magnitude summation of vertical and horizontal components was used based on the evaluation of particle motion at the surface. It was verified that proposed method could give reliable Vs distribution map through the numerical study using the FEM (Finite Element Method) model. Finally, SPT-Uphole tomography method was performed at the weathered soil site where several boring data with SPT-N values are available, and the feasibility of proposed method was verified in the field.

Acknowledgement

Supported by : 한국건설교통기술평가원

References

  1. 김동수, 방은석, 서원석 (2003) 표준관입시험을 이용한 업홀시험에서 전단파 속도 주상도의 도출, 한국지반공학회논문집, 한국지반공학회, Vol. 19, pp. 135-146
  2. 조창수, 이희일, 서정희 (2002) 탄상파 굴절법 토모그래피을 이용한 지반의 속도 분포 해석, 물리탐사, Vol. 5, pp. 6-17
  3. Lytle, RJ., Dines, K.A., Laine, E.F., and Lager, D.L. (1978) Electromagnetic Cross-Borehole Survey of a Site Proposed for an Urban Transit Station, UCRL-52484, Lawrence Livermore Laboratory, Unicersity of California
  4. Stokoe, K.H. and Rosenblad, B.L. (1999) Offshore geotechnical investigation with shear waves, in Roesset, J.M,. Ed., 1999 Offshore Technology Conference, OTC 10823, pp. 1-9
  5. Tronicke, J, Tweeton, D. R., Dietrich, P., and Appel, E. (2001) Omproves Crosshole Radar Tomography by using Direct and Reflected Arrival Times. Applied Geophysics, Vol. 47, pp. 971005
  6. 방은석, 김종태, 김동수(2006) 2방향 지표면 속도계를 활용한 SPT-업홀 기법 개선 연구, 대한토목학회논문집, 대한토목학회, 제 26권 제 2-C호, pp. 109-120
  7. 조성호, 장대우, 강태호, 이일화(2005) CAP SASW 기법에 의한 지반단면의 전단강성구조 평가, 한국지반공학회논문집, 한국지반공학회, Vol. 21 , pp. 71-81
  8. Kim, Dong-Soo, Seo, Won-Seok, Bang, Eun-Seok, 2004, Energy Ratio Measurement of SPT Equipment, international site characterization(ISC-2), Porto, Portugal, Vol. 1, pp. 339-344
  9. Zerwer, A., Cascante, G., and Hutchinson, J. (2002) Parameter Estimation in finite element simulations of rayleigh waves, Journal of Geotechnical and Geoenvironmental Engineering, Vol. 128, No.3, pp. 250-261 https://doi.org/10.1061/(ASCE)1090-0241(2002)128:3(250)
  10. 김동수, 박형춘, 김성인 (1999) 표면파시험과 공진주시험을 이용한 사질토지반 개량평가 시스템의 개발, 한국지반공학회논문집,한국지반공학회, Vol. 15 , pp. 41-52
  11. Imai, T. and Tonouchi, K. (1982) Correlation of N-value with Swave velocity and shear modulus, Proceedings of the 2nd European Symposium on Penetration Testing, Amsterdam, pp.57-72
  12. 김중열 (2000) 임해매립층/해성점토 경계면 규명을 위한 탄성파 이용 기술, 2000년 공동특별강연 논문집, 한국지구물리탐사학회 . 한국지반공학회 지반조사위원회, pp. 48-86
  13. Park, H. C. and Kim, D. S. (2001) Evaluation of the dispersive phase and group velocities using harmonic wavelet transform, NDT&E Int , Vol. 34, pp. 457-467 https://doi.org/10.1016/S0963-8695(00)00076-1
  14. Tweeton, D.R, Jackson, M.J. and Roessler K.S. (1992) BOMCRATR-A Curved Ray Tomography Computer Program for Geophysical Appication, USBM RI 9411
  15. Um, J and Thurber, C. (1987) A fast algorithm for two-point seismic ray tracing, Bull. Seismol. Soc. Am., Vol. 77, pp. 972-986
  16. 방은석 (2001) 다운홀 및 업홀을 이용한 지반의 전단파 속도 주상도의 도출, 석사학위논문, 한국과학기술원
  17. 고광범, 지준, 이두성 (2000) 천부탄성과 탐사 자료획득을 위한 3차원 측선 배열 설계, 한국자원공학회지, 한국자원공학회, Vol. 37, pp. 232-239
  18. Park, C.B., Miller, R.D., and Xia, J. (1999) Multichannel analysis of surface waves (MASW), Geophysics, Vol. 64, pp. 800-808 https://doi.org/10.1190/1.1444590